Edexcel Geography A Topic 2

What is the atmosphere?

The layer of gases surrounding Earth's surface.

What is the troposphere?

The layer of atmosphere closest to Earth's surface, approximately 10 km thick.

What drives the constant motion of air in the troposphere?

Energy from the Sun.

What is global atmospheric circulation?

The worldwide pattern of movement of air in the troposphere.

How does the curvature of Earth affect solar energy input?

It causes energy input from the Sun to vary with latitude, being more concentrated at the Equator and dispersed at the Poles.

What happens to warm air in the troposphere?

It expands, becomes less dense, and rises, producing low surface air pressure.

What are winds?

Movements of air from areas of high pressure to areas of low pressure.

What are the three convection cells in each hemisphere?

Hadley Cells, Ferrel Cells, and Polar Cells.

What is the Coriolis effect?

The deflection of winds and ocean currents due to Earth's rotation.

What are jet streams?

Fast winds at the top of the troposphere that circle Earth, blowing west to east.

What is the Inter-Tropical Convergence Zone (ITCZ)?

A calm region at the Equator where northern and southern hemisphere trade winds meet.

What is the Polar Front?

The region where warm air from the Tropics meets cold air from the Poles at 60° N or S.

What is frontal rain?

Rain produced when warm air rises over a cold air mass.

What is the Hadley circulation cell?

A circulation pattern where warm air rises at the Equator and sinks at 30° N or S.

What are trade winds?

Warm surface winds traveling from the Tropics to the Equator, deflected by the Coriolis effect.

What is the thermohaline ocean conveyor?

A vertical circulation that transfers heat from ocean surface to ocean depths, driven by cold, salty dense water sinking in Polar regions.

What is the Quaternary Period?

The current geological period that began 2.6 million years BP.

What are glacials?

Long, very cold time periods when ice sheets expand, usually lasting about 100,000 years.

What was the most recent glacial?

The Devensian glacial, lasting from 120,000 BP to 11,500 BP.

What is the impact of the North Atlantic Drift on climate?

It keeps the Norwegian coast ice-free while the Swedish coast at the same latitude is ice-bound.

How do ocean currents affect heat distribution?

They transfer and redistribute heat energy across the Earth, with about 20% of heat transfer from Tropics to high latitudes conveyed by ocean currents.

What is the role of surface winds in ocean currents?

Surface winds of the Ferrel Cell drive warm ocean currents from Tropics to higher latitudes.

What is the significance of the Polar Front in climate?

It is where heat energy is transferred from hot Tropical regions to cold Polar regions.

What happens to warm air as it rises?

It cools and water vapor condenses, leading to heavy convectional rain at the Equator.

What is the average coverage of ice sheets on Earth's surface during the current ice age?

Currently, 10% of Earth's surface is covered by ice sheets.

How long do glacial periods typically last?

About 100,000 years.

What was the most recent glacial period?

The Devensian Glacial, lasting from 120,000 BP to 11,500 BP.

How far south did ice cover during the Devensian Glacial?

As far south as Birmingham, England.

What is the current interglacial period called?

The Holocene Interglacial, which began 11,500 BP.

What are Milankovitch cycles?

Cyclical changes in Earth's orbit around the Sun that affect climate.

What are the three types of Milankovitch cycles?

Eccentricity, axial tilt, and precession.

What does eccentricity refer to in Milankovitch cycles?

The shape of Earth's orbit changing from circular to elliptical over a 100,000-year cycle.

How does axial tilt affect climate?

It varies from 21° to 24° over a 41,000-year cycle, influencing seasonal temperature variations.

What is precession in the context of climate change?

The wobble of Earth's axis over a 21,000-year cycle, affecting seasonal temperature variations.

How does solar output influence climate?

Variations in solar energy output affect the amount of heat energy received at Earth's surface.

What was the Little Ice Age?

A cooler phase from 1300-1900 linked to low sunspot numbers.

What was the Medieval Warm Period?

A warmer phase from 800-1300 associated with high solar output.

How do volcanic eruptions affect climate?

They emit ash that reflects solar radiation, causing global cooling, and gases that can cause global warming.

What evidence supports natural climate change?

Ice cores, pollen records, tree rings, and historical sources.

How do ice cores provide evidence of past climate?

They trap air bubbles that can be analyzed for CO2 content, indicating past temperatures.

What do pollen records indicate about climate?

Presence of pollen from specific plants can suggest periods of warming or cooling.

How do tree rings indicate climate conditions?

Wide rings suggest warm conditions (global warming), while thin rings indicate cold conditions (global cooling).

How do historical sources contribute to climate evidence?

Records of freezing rivers or warm weather crops can indicate past climate conditions.

What is the enhanced greenhouse effect?

The increase in greenhouse gases due to human activities, leading to higher global temperatures.

What are fossil fuels?

Natural resources like coal, oil, and natural gas that release CO2 when burned.

How does industry contribute to greenhouse gas emissions?

Machinery and chemical processes release CO2 and other greenhouse gases.

What role does transportation play in greenhouse gas emissions?

Burning fossil fuels for transport generates significant CO2 and nitrous oxide emissions.

How does agriculture contribute to greenhouse gas emissions?

Livestock produce methane, and rice farming generates methane from flooded fields.

What is the expected impact of climate change on crop yields?

Higher temperatures and lower precipitation may reduce yields, especially in tropical regions.

What is expected to happen to Southern Europe due to climate change?

It is expected to get drier as the POLAR FRONT rain belt shifts further north.

What are Hadley and Ferrell Cells, and how do they relate to climate change?

They are atmospheric circulation cells; the expansion of sinking air flows at the Tropics is expected to increase arid regions.

What impact does reduced rainfall have on farmers in developing countries?

It leads to lower crop yields, reduced incomes, and potentially food shortages and malnutrition.

What causes rising sea levels?

Melting of land-based ice sheets and thermal expansion of ocean water due to rising temperatures.

How much did global sea levels rise during the 1900s?

Mean global sea levels rose by 20 cm.

What is the projected rise in sea levels by 2100?

Projected rise is between 20 cm and 1 m.

Which cities are threatened by rising sea levels?

Houston (USA), Alexandria (Egypt), Jakarta (Indonesia), Shanghai (China), and Marseilles (France).

What is the highest point in the Maldives, and why is it significant?

The highest point is only 2.4 meters above sea level, making it vulnerable to flooding.

How does rising sea level affect coastal habitats?

It floods habitats like salt marsh wetlands, impacting populations of migrating birds.

What is the effect of rising sea levels on coastal erosion?

It increases rates of cliff erosion and coastal retreat due to deeper water conditions.

What is causing glaciers to retreat globally?

Higher temperatures are leading to increased rates of glacier melting.

What was the impact of the Columbia Glacier's retreat since 1982?

It retreated 16 km and lost half of its ice volume.

What are the potential consequences of river floods caused by glacier melt?

They could wash away buildings, interrupt transport routes, and reduce incomes.

What is the average temperature range in the UK?

Maximum average monthly temperature is 15°C; minimum is 4°C.

What type of climate does the UK have?

A temperate maritime climate with moderate temperatures and rainfall.

What causes the UK's wet climate?

It is located at the POLAR FRONT where warm air from the Ferrel Cell meets cold air from the Polar Cell, causing frontal rain.

What were the effects of the Little Ice Age in the UK?

From 1400-1850 AD, temperatures were about 0.5°C below average, leading to longer, colder winters and reduced crop yields.

What is spatial variation in climate?

It refers to the differences in climate characteristics, such as temperature and rainfall, across different locations.

How does latitude affect temperature in the UK?

Locations further north receive less concentrated solar energy, resulting in cooler temperatures.

What is the effect of distance from the sea on temperature?

Inland areas experience more extreme temperature variations compared to coastal areas due to continentality.

What is the North Atlantic Drift?

A warm ocean current that makes the west coast of the UK slightly warmer than the east coast.

How does altitude affect temperature?

Temperature drops by 0.5°C for every 100 meters increase in altitude.

What is the prevailing wind direction in the UK?

The prevailing wind direction is southwesterly, influenced by the Ferrel Cell.

What is relief rainfall?

Rainfall that occurs when moist air is forced to rise over mountains, cooling and condensing to form precipitation.

What is the source region and weather associated with tropical maritime air mass?

Comes from SW near the Azores in the Atlantic, bringing warm, wet weather.

What type of weather does tropical continental air mass bring?

Hot, dry weather from the Sahara.

What are the characteristics of polar continental air mass?

Comes from E with a source region in Russia, bringing cold, dry weather.

What type of weather does arctic maritime air mass produce?

Cold weather and snow in winter from the Arctic Ocean.

How does the polar maritime air mass affect the UK?

Comes from NW across Greenland, bringing cold, wet weather.

What climate does the UK experience due to its maritime location?

Mild, moderate climate without extremes of temperature.

Why does water have a higher specific heat capacity than land?

It takes more energy to raise water temperature by 1°C and loses energy more slowly.

What is the average December temperature in Moscow compared to London?

Moscow: -12°C; London: +4°C.

What are tropical cyclones and where do they form?

Intense low pressure systems that form between the Tropic of Cancer and Tropic of Capricorn.

What is the sequence of formation for tropical cyclones?

Solar heating warms ocean water, causing evaporation, rising air, and convection currents that lead to cyclone development.

What role does the Coriolis effect play in tropical cyclones?

It causes the rising air to spin, contributing to the cyclone's rotation.

What are the characteristics of tropical cyclones?

Very low air pressure, strong winds (120-400 kph), and cumulonimbus clouds reaching the troposphere.

What is the Saffir-Simpson Scale?

A classification system for tropical cyclones based on wind speed and storm surge data.

What impacts do tropical cyclones have on emerging countries like Cuba?

Economic losses, social disruptions, and environmental damage, including destruction of homes and infrastructure.

What is the average frequency of tropical cyclones each year?

About 80 tropical cyclones form annually, with variations based on climate conditions.

How does climate change affect tropical cyclones?

It is likely to produce more intense cyclones and expand their distribution to higher latitudes.

What are the hazards associated with tropical cyclones?

High winds, intense rainfall, storm surges, coastal flooding, and landslides.

What is the impact of storm surges from tropical cyclones?

They can cause significant flooding, damage to buildings, and erosion of coastal habitats.

What conditions increase the risk of landslides during a tropical cyclone?

Deforestation, construction on steep slopes, and permeable geology underlain by impermeable layers.

What was the impact of Hurricane Sandy in October 2012?

It caused extensive damage in Cuba, including destroyed homes and significant economic loss.

What are the consequences of intense rainfall from tropical cyclones?

Flooding, damage to crops, and overwhelmed drainage systems leading to urban flooding.

What is the typical size of the eye in a tropical cyclone?

30-50 km across, characterized by calm conditions.

What happens to air in the eye of a tropical cyclone?

Sinking air creates dry conditions and clear skies.

What is the role of latent heat in tropical cyclones?

It is released when water vapor condenses, contributing to the cyclone's energy and intensity.

What was the impact of Hurricane Sandy on Santiago de Cuba?

430,000 people lost electricity and piped water, with 55,000 evacuated from their homes.

What environmental impacts did Hurricane Sandy have in Cuba?

Storm surge and destructive waves swept away sand from beaches, blew down trees, and caused landslides inland.

What was the economic impact of Hurricane Sandy in the USA?

Total damage was estimated at $19 billion, including damage to 100,000 buildings and a shutdown of the New York Stock Exchange.